swingactors.scala

// ©2012 Viktor Klang

package akka.klang

import akka.dispatch.{ DispatcherPrerequisites, ExecutorServiceFactory, ExecutorServiceConfigurator }
import com.typesafe.config.Config
import java.util.concurrent.{ ExecutorService, AbstractExecutorService, ThreadFactory, TimeUnit }
import java.util.Collections
import javax.swing.SwingUtilities

// First we wrap invokeLater as an ExecutorService
object SwingExecutorService extends AbstractExecutorService { 
  def execute(command: Runnable) = SwingUtilities.invokeLater(command)
  def shutdown(): Unit = ()
  def shutdownNow() = Collections.emptyList[Runnable]
  def isShutdown = false
  def isTerminated = false
  def awaitTermination(l: Long, timeUnit: TimeUnit) = true
}

// Then we create an ExecutorServiceConfigurator so that Akka can use our SwingExecutorService for the dispatchers
class SwingEventThreadExecutorServiceConfigurator(config: Config, prerequisites: DispatcherPrerequisites) extends ExecutorServiceConfigurator(config, prerequisites) {
  private val f = new ExecutorServiceFactory { def createExecutorService: ExecutorService = SwingExecutorService }
  def createExecutorServiceFactory(id: String, threadFactory: ThreadFactory): ExecutorServiceFactory = f
}

// Then we simply need to create a dispatcher configuration in our application.conf

swing-dispatcher {
  type = "Dispatcher"
  executor = "akka.klang.SwingEventThreadExecutorServiceConfigurator"
  throughput = 1
}

// After that we just create the GUI Actors with a Props with the correct dispatcher set:

val frameActor = context.actorOf(Props[FrameActor].withDispatcher("swing-dispatcher"), "frame-actor")

// Done! Now all messages processed by "frameActor" will be executed by the Swing Event Dispatch Thread, enjoy!